Section 3 or full registration labels are approved uses for a pesticide. For a full registration the manufacturer is required to submit scientific data on the pesticide toxicity and behavior in the environment and human health risks and is required to include testing protocols for pesticide residues.  Based on the submitted data, the EPA will define the approved uses and conditions of use including rates and timing of applications.

Section 2(ee) or additional use recommendations are recommendations put forth by manufacturers that advocate the use of a registered product on a pest that is not specified on the label, as long as the pest is present in a crop for which the pesticide is labeled and the EPA does not require a separate label for the pest in question.
 
Section 18 or emergency use labels authorizes EPA to allow States to use an unregistered active ingredient or an additional use for a registered pesticide on a non-registered crop or site for a limited time if EPA determines that emergency conditions exist.

Section 24(c) or special local needs labels gives individual states the authority to add uses based on special local needs to pesticides already registered for other uses.
 
I want to call special attention to section 2(ee) labels because they are, in a sense, a curious lot.  Any Section 2(ee) recommendation is, as is stated on the recommendation itself, neither submitted not approved by EPA. 

What does that mean?  Simply put - EPA has not reviewed any data of the product in question in relation to the pest for which this recommendation is made by the manufacturer.  The manufacturer can make the recommendation because the rates, timing of applications etc all fall within the full registration (Section 3).   Efficacy of the product to control the pest in question is not a consideration as far as EPA is concerned.

Just because a Section 2(ee) recommendation is available it doesn’t imply that the pest in question is an economic problem or that the product has any efficacy. We can only assume the product mentioned in the Section 2(ee) recommendation has some efficacy against the pest in question. 

This brings me to the next point - a recently published Section 2(ee) recommendation to suppress or control wheat stem maggot in spring wheat and winter wheat. 

Wheat stem maggot (Meromyza americana Fitch) is a minor pest problem in wheat production regions from Mexico to Canada (Figure 1). The adult flies are yellowish-white, about 1/5 inch long, with three black stripes on the thorax and abdomen and with striking, bright-green eyes. In Minnesota and North Dakota the adults emerge in late May and June after overwintering as larvae. These adults will lay individual eggs near the base of leaves. After the eggs hatch, the ¼” maggots burrow inside the stem of the upper most joint of the host plant and begin feeding, thereby cutting off nutrients to the developing heads and causing distinct, white heads. Larvae which damaged wheat emerge as flies in late summer to mate and lay eggs on grasses in which the larvae will overwinter.
 
To date no single extension service across the country has published a threshold to spray against wheat stem maggot. The effectiveness of insecticides and the proper timing are unknown. It is recommended to control this pest with crop rotation and other cultural practices such as destruction of volunteer plants in early fall and delayed planting (winter wheat). There are no resistant varieties for this pest.
 
Simply put – just because we have a 2(ee) recommendation for suppression or control of wheat stem maggot doesn’t mean that we have an economic problem or an effective means to control that pest economically.

Jochum Wiersma, Small Grains Specialist
U of MN Extension, NWROC-Crookston